Phase changer



L. HlMMEL PHASE CHANGER June 25, 1946.

2 Sheets-Sheet 1 Filed. Jan. 8, 1943 mmvron. LEON HIMMEL Patented June25, 1946 UNITED STATES PATENT OFFICE PHASE CHANGER Application January3, 1943, Serial No. 471,767

15 Claims. 1

Thisinvention relates to improvements in phase changers, and moreparticularly to a device for changing phase in a" high frequencytransmission line.

An object of this invention is to provide a truly aperiodic" phase"changer for use with high frequency transmission lines.

A further object of this invention is the provision of a phase changeroperating on a section of a transmission whose characteristic impedanceis always matched tothat of the main transmission l'ine; while the wavepropagation velocity may be varied at will.

A still further object of this invention is the provision of aphasechanger which is operated by the insertion of a movable member betweentwo'conduct'ors of a high frequency transmission line section, thismember being so designed as to provide a constant L/C transmission lineratio and a variable LCtransmission line product depending upon itsposition, whereby the wave propagation velocity of the transmission linemay be varied in accordance with the position of the member; while itscharacteristic impedance will be" maintained constant.

Still-another object of this invention is to providea phase changeroperating in the manner above described without necessitating the use ofany'sli dable or otherwise relatively movable contacts.

Other objects and advantages of the present invention will appearf'romthe 'following detailed description of a preferred embodiment and'modifi'cation thereof, illustrated in' the accompanying drawings; inwhich:

Fig. 1 is-a verticalplan view, partially broken away, of an improvedphase changer in accordance with the present invention;

Fig; 2 is a vertical section'takenalong the line 2-'-2 of Fig. 1-;

Fig. 3 is a transverse section taken along the line;3''3 ofFig. I;

Fig. 4 is a transverse section taken along'the line44'of Fig. 1; V

Fig. 5 is a plan view' illustrating the manner in which the transmissionline section of the phase changer is interconnected with the rest of thetransmission linewhosephase is to be controlled; and

Fig. 6 is a vertical cross-sectional view of a modified phase changercontrol member.

As more particularly'shown in Figs. 1, 2 and 3, the phase changer inaccordance with the present invention is preferably mounted in agenerally extending conductor bars 40 and. 40'.

of a rear panel [0 having vertically extending bent-over strengtheningsections l2 on either side andintegral forwardly extending top andbottom sections Hand M. The top and bottom sections I4, I4 arepreferably turned inwardly at their forward ends to form respectivetransverse fianges l6. IS. The top and bottom transverse fianges l6, l6are interconnected by vertically extending angle irons I8 and IS onopposite sides of the framework by' means of suitable corner angles [9attached to the vertical angle irons and the turned over flanges l6, I6in any suitable manner, as by welding. A series of mounting lugs 20 willbe' attached to the rear panel In to permit mounting of the phasechanger unit in a suitable control rack. A transverse sheet metal member22 is connected across the vertical angle irons l8 and I8 throughsuitable means such as screws 24'. The transverse member' 22 serves tostrengthen the framework and also acts as a mounting for a suitableindicator to be described in more detail hereinafter. The front andsides of the phase changer may be enclosed by a removable cover 26 toprovide a completely enclosed dust-proof unit.

At both the top and bottom of the framework and within the same areprovided a pair of generally U-shaped supports 28, each having spacedapart inwardly extending legs 30' and an extended base 32 connected tothe top and bottom sections of the frame by suitable means such as bolts34. Between each of the arms 30 is mounted an insulating block 36, beingfirmly attached between the legs by means such as through bolts 38. Theinsulating blocks 36 are attached to receive and support in spacedparallel relationship vertically The conductor bars 40 and 40 arepreferably T-shapecl with the leg of the T' projecting into thesupporting insulating blocks and the tops of the Ts being opposed to oneanother in parallel spaced relationship. The conductor .bars 40 and 40and, more particularly, their legs inserted in the insulating blocks 36are held in place by the use of suitable clamping bolts 42 and 42'.

A control member 44 is positioned between the conductor bars 40 and 40'for varying wave propagation velocity along the conductor bars inaccordance with its relative position between these bars. The controlmember 44 extends vertically substantially the length of the conductorbars and, as is most clearly shown in Fig. 3 is preferably formed of ametal section 46 rigidly connected as a unit to a dielectric section 48.The

3 dielectric section 43 is solid at one end, being provided with a pairof forwardly extending legs 50 between which a reduced portion 52 of themetal section 46 is inserted. Legs 50 of the dielecric section areinterconnected with the reduced portion 52 of the metal section bysuitable means to such as screws 54 to form, in effect, an integrallycombined metal and dielectric control unit. In the form of control unitillustrated, the main part of the metal section 46 is made hollow, thesmall section 52 thereof being formed as integrally continuous legs ofthe hollow member. While this construction is not necessary for thepurposes of the present invention, it provides a saving of metal over asolid metal section and is the electrical equivalent of the latter. Thetop and bottom of the hollow metal section 42 are closed by metal blocks56, rigidly attached within the metal section in any suitable manner asby soldering orbrazing, the blocks 55 serving as partial supports formetal end members 58 and 50'. These metal end members are attached tothe control member 44 in any suitable manner and are provided withthreaded through openings receiving threaded shafts 60 and 60. The shaft60 is sufliciently long to extend through and outside of the cover 26and on this outer end there is attached a suitable crank 62. AVertically extending shaft 64 interconnects the threaded shafts 60 and60' by means such as bevelled gear pairs 66 and 68. The front end of theshaft 60 and the upper end of the shaft 64 are journalled in a suitablydesigned support I which may be, in turn, connected to top I4 of theframework while the front end of the shaft60 and the lower end of theshaft 64 are journalled in a comparable bearing member 12 connected tothe bottom I4 ofthe framework. The rear end of the shaft 60 may bejournalled in a member I4 which may also serve as a strengtheningbracket between the rear panel I0 and the bottom I4 of the framework,while a similar member I0 connected between the rear, panel I0 and thetop I4 of theframework serves to support the rear of the threaded shaft60.

It will be clear to those skilled in this art from the foregoingdescription that rotation of the crank 62 rotating, as it does, thethreaded shaft 62 and, through the vertical shaft 64, the threaded shaft60', will result in an in and out movement of the control member 44,depending upon the direction of rotation, between the conductor bars 40and 40'.

The conductor bars 40 and 40' are preferably a section of a transmissionline which may include spaced apart conductors I8 leadinginto the phasechanger and the spaced apart conductors 18' from the phase changer.Connection between the conductors of the transmission line and theconductor bars of the phase changer forming a transmission line section,is preferably brought about in a manner such as shown in more detail inFig. 4. As there illustrated, the conductors I8 are inserted intoopenings in small metal blocks 80 and 80 and rigidly attached thereto asby soldering. At the extreme ends of the conductor bars 40 and 40', onthe other hand, are rigidly connected, also as by soldering, smallsimilar metal blocks 82 and 82.- The actual electrical connectionbetween the conductors I8 and the conductor bars 40 and 40' is thenaccomplished by attaching the block to the block 82 and the 4 tion whichis both mechanically strong and of low electrical resistance.

The input transmission line conductors 18 are, as is usual, positionedwithin a suitable shield 86, while the output transmission lineconductors "I8 are positioned within a suitable shield 88 which, if itis desired to have both the input to and the output from the phasechanger positioned at the same end, will run through the phase changer,as illustrated. The output transmission line conductors I8 will beconnected to the lower end of the conductor bars 40 and 40' in themanner described above in connection with Fig. 4 and will pass through asuitable external connector, which may be of the type indicated at 90 inFigs. 1 and 2. The conductors of the transmission line will be properlypositioned within their respective surrounding shield by means such asinsulating disks 92.

In order that the relative position of the control member 44 between theconductor bars 40 and 40' may be indicated, the phase changer may beprovided with a suitable scale 94 cooperating with a movable indicatorarm 96. The scale 94 may be formed on the front face of a generallyU-shaped member 98, the legs of which are connected to the transversemember 22, previously described, as by screws I00. The forward end ofthe indicator arm 96 will project through a suitable opening in thefront of the U-shaped member 98, along which opening the scale 94 may bepositioned, while the rear of the indicator arm 90 is inserted into amember I02 pivotally supported relatively to the member 22 by suitablemeans such as brackets I04. Rotatable as a unit with the member I02, isa generally inwardly and downwardly extending arm I06 whose lower end ispivotally interconnected with a link I08 which, in turn, is pivotallyattached to a support I I0. The latter is fastened to the front verticalface of the control member 44 by suitable,

means such as screws II2. It will be at once clear that movement of thecontrol member 44 will be transmitted through link I00 and the arm I06to the indicator 96 so that the position of the latter will give an,indication of the relalive position of the control member 44.

The phase changer which hasbeen described above in more detail fulfillsthe objects and realiZes the advantages of the invention. The controlmember 44 is so designed and proportioned that a change in phase or achange in the wave I mission line to be controlled. Spacing theconductor bars 40 and 40' further apart will'immediately increase theinductance, and decrease the capacitance of this transmission linesection and will thus increase the characteristic impedance of thatsection. As a result, the transmission line section comprising theconductor bars 40, 40' would not be matched to the rest of thetransmission line. However, by the insertion ofthe control member, forexample, the metal section 46 thereof, the effective inductance whichwas increased by separating the conductor bars could be reduced to itsoriginal value, the, capacitance is increased and the transmission linesection of the phase changer will be again matched to the rest of. thetransmission line. Now, for. example, it the control. member 414 is somoved. that the dielectricsection 48iispositioned between the conductorbars 410- and 40 the surge impedance of the transmission line section ofthe phase changer may be maintained at the same value as when the metalsection 46 was'between the conductor bars provided that the L/C ratio.of this transmission line section. is maintained constant. A properproportioning of the dielectric section 48, characteristic of thecontrol member in accordance with this-inventioncan effect this result.The dielectric section 4% is so designed that although metal has beenremoved from between the conductor bars 40 and 40', thusraising thevalue of L, the dielectric constant of the dielectric section 4 8. issuch that C has been raised an equal proportional value. so that theratio of L/C remains constant and thus the characteristic impedance ofthe transmission line section has not been altered. On the other hand,the wave propaga tion velocity'is inversely proportional tothe prodnot.of. L C and since both L and C are now larger, as compared to theconditions when the metal section 46- was between. the conductor barsthe wave propagation velocity and thus the phase has been changed. Thesection of the control member. 44 which includes the reduced metalsection. 52 and the dielectric legs Ellis so designed to give anintermediate value of. wave propagation velocity, butstill soproportioned that the characteristic impedance or the L/C ratio remainsconstant. At the same time, it will be noted that no sliding orotherwise relatively movable contacts are necessitated by the presentinvention. Hence there will be no poor contact due tocorrosion ofsurfaces.

The control member 44 may be constructed in various ways so long as theessential characteristics of the present invention are maintained. Forexample, the control member may have a shape such as exemplified by thecontrol member 244 of Fig. 6. Instead of the stepped configurationillustrated in the preferred embodiment, the control member 244 providesa more gradual change in phase by using a wedge-shaped metal section 246enclosed on either side by oppositely directed wedge-shaped dielectricsections 248 and 248'. The parts may be connected together to form anintegral unit by means such as screws 254. The manner of operation ofthe control member 244 will be identical with the principleof operationof the control member 44, provided that the metal and dielectricsections are so proportioned that the L/ C ratio of the transmissionline section of the phase changer is maintained constant while, as inthe manner previously explained, the L C product will vary, It iscontemplated that other configurations of metal and dielectric controlmember units having the desired characteristics may be formed as willoccur to those skilled in this art.

While, for the sake of clarity, I have described in some detail aspecific embodiment and modification of phase changer unit embodying theprinciples of my invention, it is to be clearly understood that theinvention is not to be considered as limited to the specific structuralfeatures shown and described, but that various changes can be madewithout departing from the spirit and scope of the invention as outlinedin the objects thereof and embodied in the claims that follow.

What is claimed is:

1. A phaser comprising, in combination, a

6. transmission line section having a pair of parallel spaced apartconductors, and a member transversely movable: between said conductorsand extending substantially the length of said. transmission linesection, said member consisting. of a metal section at one transverseend, a dielectric section at its other transverse end, and combinedmetallic and dielectric sections intermediate its transverse ends, thewidth of the dielectricsection and of the intermediate metallic anddielectric sections. being greater than. the width of the metallicsection alone in such auproportion' that the L/C ratio of the lineremains constant; no matter which portion of said member is positionedbetween said conductors, and means. for moving said member transverselybetween said conductors so as to position diflerent sections thereofvintermediate said conductors for varying the velocity of wavepropagation along said conductors while maintaining said transmissionline section constant.

2.. The combination according to claim 1, in which said member consistsof a metal section at one end having a predetermined width. for aportion of its length and a smaller predeterminedwidth for anotherportion of its length, a first dielectric section at the other endhavinga predetermined width for a portion of its length and a smallerdielectric section extending on opposite sides of said reduced metalsection in the direction of said conductors.

3. A combination according to claim 1, in which said. member consists ofa metal-section decreasing in. width from one end of said member to theother, and a pair of dielectric sections increasing inwidth from the oneend of the member to the other, attached tothe opposite lateral faces ofsaid metal section.

4. The combination according to claim 1, in combination with means forindicating the relative position of said member between said conductors.

5. A phase changing unit comprising a transmission line section having apair of spaced apart substantially parallel conductors, and a metal anddielectric means transversely movable between said conductors forvarying the inductance and capacitance of the transmission line in equalproportion so that the L/ C ratio of the surge impedance of the lineremains constant, while the velocity of wave propagation is varied inaccordance with the position of such means between the conductors.

6. The combination according to claim 5, in which said means comprises amember consisting of varying overlapping metal and dielectric sections,the metal section having its greatest diameter at one end of said memberin the direction of movement thereof, and the dielectric section havingits greatest dimension at the other end of said member.

7. The combination according to claim 5, in which the said meanscomprises a member consisting of a. metal section at one end having apredetermined width for a portion of its length and a smallerpredetermined width for another portion of its length, a firstdielectric section at the other end having a predetermined width for aportion of its length, and a small dielectric section extending onopposite sides of said reduced metal section in the direction of saidconductors.

8. The combination according to claim 5, in which said means comprisesa. member consisting of a metal section decreasing in width from one 7vend of said member to the other, and a pair of dielectric sectionsincreasing in width from one end of the member to the other attached tothe opposite lateral faces of said metalsection. V

9. A phase changing unit, comprising, in combination, a supportingframework, a pair of spaced apart and co-planar conductor bars extendinglongitudinally Within said. framework, insulating means for andsupporting said pairs in said framework, a control membervpositionedbetween said conductor. bars, said control members having a lengthsubstantially equal to the length of said bars, a depth substantiallygreater than, the thickness of said bars, and a width of variable crosssection, said control member be-' ing formed as a unit consisting of ametal portion of relatively small cross section, decreasing to a stillsmaller cross section, and a dielectric portion having a relativelylarge cross section decreasing to a smaller cross section overlappingthe smaller cross section of the metal portion, and means supported bysaid framework for moving said control member transversely between saidbars for inserting different cross sections of said member directlybetween said bars.

10. The combination according to claim 9, in combination with meanssupported by said framework for indicating the position of said controlmember between said bars.

11. The combination according to claim 9, in combination with threadedend pieces attached to opposite ends of said control member, and inwhich said moving means includes threaded shafts engaging said threadedend pieces, a longitudinally extending shaft, gears interconnecting saidlongitudinal shaft with both of said threaded shafts, and a crank on oneof said threaded shafts.

12. The combination according to claim 9, in which the metal portion ofsaid control member continually gradually decreases in cross, sectionand the dielectric portion .is formed'as two sec! tions on oppositesides of the metalportion, each section continually gradually decreasingin cross section from the smaller to the larger part of the metalportion. a v

13. The combination according to claim,9, in which the metal portion ofsaid control member decreases in cross section in step-by-step fashionand the dielectric portion decreases in cross section in step-by-stepfashion, the smallest cross sectional sectionof the dielectric portionbeing split and positioned on opposite sides of the smallest metalsection. V V

14. The combination according to claim 9, in combination with metalblocks internally rigidly attached to the end of each conductor bar, andconductor-receiving blocks having conductor-receiving openings removablyattached to said metal blocks between the conductor bars, the distancebetween the conductor-receivingopenings in the conductor-receivingblocks at each end being substantially less than the distance betweenthe corresponding conductor bars to which they are attached by saidmetal blocks.

15. In combination, a transmissionline having a pair of spacedconductors providing a predetermined characteristic impedance, a sectionof said transmission line having a. pair of more widely. spacedconductors providing a greater characteristic impedance, and a metal anddielectric means positioned between the said Widely spaced conductors toreduce the characteristic impedance of said section to that of the restof the transmission line, said means including means for varying thevelocity of wave propagation alongvthe line.

LEON HIMMEL.

